Reenforcing bar for concrete construction



Nov. 11. 1924. 1,514,806 I F. L. THOMAS REENFORCING BAR FOR CONCRETE CONSTRUCTION Filed Dec. 1, 1922 37/. .B 4/ 3 MQM Patented Nov. 11, 1924.

NITED STATES PATENT OFFICE.

FRANK 1.. THOMAS, or nurrn'nannw YORK. ASSIGNOR TODO'NNER STEEL COMPANY,

- me, or BUFFALO, NEW YORK.

REENFORCING BAR' FOR CONCRETE CONSTRUCTION.

Application filed' December 1,1922.

following is a specification.

This invention relates to improvements in reinforced concrete construction.

Many types of metal bars have heretofore been used in connection with reinforced concrete constructions, and some of these types are well adapted for one kind of work and other types may beused to better advantage onother work. A rectangular, oblong bar is desirable for the reason that its surface area per unit of length is greater than that of a-square or round bar, and therefore i is more firmly bonded tothe surrounding concrete. Rectangular, oblong bars, however, as well as oval bars, ,are' objectionable in that they may be easily bent in one planeonly. Square bars are more desirable than rectangular bars in that they can be readily bent in two planes, but have less surface area, and round bars can be readily bent in any direction, but have still less surface area for a given cross sectional area than either square, oval or rectangular bars. Square and rectangular bars, and some types of deformed bars also have the disadvantage that the corners thereof form re-entrant angles in the surrounding concrete, which start cracks in the concrete. Bars of other shapes have been devised with the-view of overcoming the objections to. the-round, oval, square and .rectangularbars, but'these bars embody other defects when used in concrete construction or are diflicult to roll, so that" these bars are expensive to produce.

The objects of. this invention are to provide a bar of this kindwllich is so formed that when used in. connection witlr concrete construction, the bar is superior to rectangular, square or oval bars now used, and also embodies certain improvements over bars of round or circular cross section,

as well as over bars of other/shapes; also; to provide ,,a.,bar of this kind which is fsuperior to bars heretofore provided in respect to the cost at which the bar can be manufactu'red, especially in thatmy improved Serial No. 604,201.

bar can be manufactured with less loss'diua 'to imperfections, and from rolls that are r ,ing bar embodying the invention. metalbars of the kind adapted tonnes in Figs. 3 and .4 are, sections thereon on lines 3 3 and 4-4, Fig. 1.

Fig. 5-is a, perspective view of a portion of a reenforcing bar.

The core A of the ,bar embodying the invention is uniform in cross section,- and as shown at a, and the sides or portionsbetween edges are concaved or fluted, as at a. The concaved sides or fluted portions,

however,"a're shallow so that the concrete will readily flow into the concave sides and so that the' bar can readily be bent in all planes passing through the axis of the bar. By rounding the portions a'of the bar, no re-entrant angles are formed which cause cracking of the concrete. The cross section of the core of the bar, as shown particularly in Figs. 3 and 4, is ofsuch form that the perimeter thereqigf is approximately the same as the periineter of a square of the same area. Consequently, a bar of this cross section has the same surface exposed for bonding-with the surrounding concrete as a square bar, but overcomes the objection of the re-entrant angles of the square bars and also overcomes the objections to square bars that they are only capable of being bent in two planes.

The bar is also provided with two series of transverse ribs B and B, each of the ribs extending half way round the bar.

The'series of ribs B is arranged on one side of the bar and the ribs B are arranged on the other side thereof, and the two series are so arranged that arib on one side of the bar is intermediate between adjacent bar to twist whenleaving therolls, which manufactured, since all of the machining of the rolls can bedone by milling cutters,

ribs of the other side of the bar, thus forming a stag ered arrangement of the ribs. These ribs%3 and B are so arranged that the ends of the ribs merge .intothe. longitudinal, rounded edge portions a at diametrically opposite sides of the bar, and the transverse ribs preferably extend slight- 1y beyond the other longitudinal edge portions a. When the concrete is poured around the bar described, the ribs become embedded in-the concrete so that longi tudinal movement of the bar inthe concrete is prevented.

The bar described, vantages when used in conn'ectionw-ith reinforced concrete construction, also has de cided advantagesfrom the standpoint of its production in a. rolling-mill. In thefirst place, the rolls used in connection with the manufacturing of this bar can bevery easily and no hand work of any kind is required on the rolls. The rolls are somade that one of thescries ofribs is formed by one roll. while the ribs ofithe other 'series'are formed by the other roll, and-by arrangingthcse ribsin staggeredrelation, as shown, an accurate athustment of the rolls with re-- gard to each other in sucha manner that the rib-forming portions of one roll always register in adefinite relation to the ribforming portions of another roll, is not necessary. the ribs of one side of the bar with refer' ence to the ribs of the other side is of no importance. machining of the rolls'as well as in the recutting of the rolls after theybecome worn,

no particular attention need'be paidto hay ing the rib-forming,portions of one roll veryimperfection in rolling is reduced to amini-' mum. Also;,due to the shape of the core of the bar, t is easier to get and to mamtam the true section when rolling than with other deformed bars'heretofore used, whereby a greatly increased production is obtained.

, The bardescribed embodies all of the good features of bars of round and square cross section, and overcomes all of the objections of these bars. Furthermore, the material in the" core "of" the" bards-uniformly and I compactly arranged about the longitudinal axis in addition toits ad-- A variation in thellocation 0f Consequently, in. the original of the bar so that every pa-rt'of thefcore is employed in resisting tensional oi" compres- The longitudinal, rouned sion stresses. edges do not project far enough from the concaved portions of the sides of the bar to crack or buckle when the bards bent, and

consequently the bar developsat all times and underall conditions of use the full, tensilestrength of the metal of the core.. Furthermore, the shape of the bar is such that the same cannot be twisted in the concrete when SUbJGCfQd to torsional stresses, as sometimes happens it round bars are used. The bar may also be easily bent; in any direction with reference to its longitudinal axis. The arrangement of the metal in the core "about th longitudinal axis is" such that 1 the bar is stiller under compressive strains than any other existing types on the market and is therefore better adapted for reen-' forcing columns and for other reinforced I concrete wo'r than other bars now in use. i

I claim asmy invention: i 1. A reenforcin'g bar for concrete 7 construction including a core having a cross section simulating a polygon of more than four sides, the edge portions ofthe core be ing rounded and the sides being concaved so that the periphery of the cross section will be greater than that of the polygon of corresponjdlng 'cross sectional area, and two series of transverse r1bswh1ch are arranged substantially I semicircular in form "and WlllC-ll extend acrossthespace between adjacent longitudinaledge portions of the core,

at opposite sides of the bar and whichare the ribs 01 the series being arranged in stag= V gercdrelation to each other; I

2. A reenforc-ing bar for concrete construc-' tion' including a core, the cross-section of which simulates a polygon, the edges of the core being roundedand the portions of thecore between the edges being'provided with'shallow depressions to provide a core which has a large surface area and which resists twisting when embedded inconcrete. and two series of transverse ribsarrangedat opposite sides of the core, the ends of the transverse ribs merging intodiametrically opposite longitudinal edge' p'ortion'of the bar, the ribs of one series beingarranged in staggered relation to the ribs of the other.

series.

' 3. A reenfo-rcing bar for concrete construe 1 t1on including a core,-the cross section of which simulatesa polygon having an even number of'sides greater than =four,-the edges of thecore being rounded and'the sides be ing co-ncaved,-form1ng a'core with a wavelike. periphery, and two series of transverse ribs, the ribs-of each series encircling half of the barand the ribs of one series being staggered with regard to'the ribs of the other series.

' FRANK L. THOMAS. 

